OBJECTIVE: DESCRIBE THE GENERAL STRUCTURE OF THE ATOM, AND EXPLAIN HOW THE PROPERTIES OF THE FIRST 20 ELEMENTS IN THE PERIODIC TABLE ARE RELATED TO THEIR ATOMIC STRUCTURES Atomic Structure
Dec 30, 2015
OBJECTIVE: DESCRIBE THE GENERAL STRUCTURE OF THE ATOM, AND EXPLAIN HOW THE PROPERTIES OF THE FIRST 20 ELEMENTS IN THE PERIODIC
TABLE ARE RELATED TO THEIR ATOMIC STRUCTURES
Atomic Structure
Brainstorm
What is matter? Give at least three examples. Give two examples of
things that are NOT matter, (Hint: thoughts).
What is mass? What is an atom?
Give at least three examples of things in this room that are made of atoms.
Is the air we breathe made of atoms? Explain your answer.
What is a scientific theory?
The Basics
Matter: Anything that takes up space and has a mass. Examples: a desk, a person, oxygen Non Examples: feelings, thoughts
Mass: A measure of how much matter an object contains. Mass is related to weight.
Element: A substance that can not be broken down into a more simple substance. Example: Gold, Oxygen, Carbon, Helium, Iron
The Basics
Compound: A substance made of two or more elements. Example: CO2 , H2O
Theory: A tested explanation with supporting evidence. Can be changed, revised or disproved. Example: Theory of Evolution-The change in physical
traits in a population over long periods of time.
Discussion
Can scientist be proven wrong? Can science theories be changed?Is science a process that is continually
worked on or is it set in stone? Do many people usually contribute science
knowledge?
Discovering the Atom
Aristotle: Greek Philosopher 322 BC-384BC Believed that four
elements made up all things
Discovering the Atom: Dalton’s Contribution
John Dalton England 1776 Science Teacher Atom looked like a ball
Theory: All matter is made up of individual particles called atoms, which cannot be divided.
Discovering the Atom: Ernest Rutherford
Rutherford: 1900 New Zealand Discovered protons
and nucleus Electrons move
randomly in space
Discovering the Atom: Schrodinger and Chadwick
Erwin Schrodinger: 1926 Describes motions of
electrons Leads to electron
cloud theory James Chadwick
1932 Confirms the existence
of neutrons Nucleus contains
neutrons and protons
The Atom – “Uncut” or “Indivisible”
The smallest part or unit of an element.
Cannot be broken down without losing its properties
Basic building block of matter
Makes up all physical things
Parts of the Atom
1. Protons Positively charged sub-
atomic particle Found in the nucleus
2. Neutrons Neutrally or no charge Subatomic particle found
in the nucleus 3. Electrons
Negative charge Subatomic particle found
outside of nucleus Nucleus
Dense center of the atom Positive charge
Atomic Number
The number of protons for any given element All element of one kind
have the same number of protons Example: All Hydrogen (H)
atoms have just one proton Atoms of different
elements have different number of protons
Atomic number also gives us the number of electrons
Discuss
What charge are protons?What charge are electrons?Why do you think atoms have the same
number of protons and electrons?
Neutral Atoms
The positive protons and negative neutrons balance out.
This make the charge of an atom neutral or zero.
Draw an Example
Mass Number
The number of protons and neutrons found in the nucleus Protons + Neutrons =
Mass Number Example: Carbon has a
mass number of 12
This means there are 6 protons and 6 neutrons
*Do the math
Energy Levels and Orbitals
Each ring of the Bohr Model is an energy level
As you go further out from the nucleus the energy of the electron becomes greater
Electrons orbit around the nucleus much like the earth orbits around the sun
Electron Configuration
Configuration = Arrangement Desks in the classroom are arranged in a
specific wayElectrons are found in orbits around the
nucleus. This is their “electron configuration”